Computer Architecture Semester: III Credits: 6 (2+1) Lecture 1

All assignments are INDIVIDUAL! SEE University values academic integrity. Therefore all students must understand the meaning and consequences of cheating, plagiarism and other academic offences under the Code of Student Conduct and Disciplinary Procedures.

Background Reading – Basic Texts 1. William Stallings: Computer Organization and Architecture – Designing for Performance (5/E 2001, or 6/E 2003), Prentice Hall ( course main text book ). 2. Andrew Tanenbaum : Structured Computer Organization, Prentice Hall, (some parts) 3. John L. Hennessy, David A. Patterson: Computer Architecture: A Quantitave Approach, 3/E May, (some tutorial exercises )

Internet Resources- Web site for book —links to sites of interest —links to sites for courses that use the book —errata list for book —information on other books by W. Stallings —Math —How-to —Research resources —Miscellaneous

Internet Resources- Web sites to look for WWW Computer Architecture Home Page CPU Info Center ACM Special Interest Group on Computer Architecture IEEE Technical Committee on Computer Architecture Intel Technology Journal

Computer Architecture Computer Evolution and Performance

What is Computer?

Computer Evolution and Performance What is a Computer ?! Architecture & Organization ! Structure & Function ! Evolution & Performance !

What is a Computer ? Historically, a computer was a job title, not a piece of equipment! Requirements of a computer: – Process data – Store data – Move data between the computer and the outside world – Control the operation of the above

Computer Evolution and Performance What is a Computer ?! Architecture & Organization ! Structure & Function ! Evolution & Performance !

What is a Computer Architecture? Main purpose of computer architecture is to design computer with aim to fulfill users requests. Those aim can be achievable by intervening in: —Hardware level —Software level —User level

Architecture & Organization 1 Architecture is those attributes visible to the programmer —Instruction set, number of bits used for data representation, I/O mechanisms, addressing techniques. —e.g. Is there a multiply instruction? Organization is how features are implemented —Control signals, interfaces, memory technology. —e.g. Is there a hardware multiply unit or is it done by repeated addition?

Architecture & Organization 2 All Intel x86 family share the same basic architecture The IBM System/370 family share the same basic architecture Organization differs between different versions

Computer Evolution and Performance What is a Computer ?! Architecture & Organization ! Structure & Function ! Evolution & Performance !

Structure & Function Structure is the way in which components relate to each other Function is the operation of individual components as part of the structure

Function All computer functions are: —Data processing —Data storage —Data movement —Control

Functional view

Function: Operations (1) Data movement

Function: Operations (2) Storage

Function: Operation (3) Processing from/to storage

Function: Operation (4) Processing from storage to I/O

Structure - Top Level

Computer Main Memory Input Output Systems Interconnection Peripherals Communication lines Central Processing Unit Computer

Structure - The CPU Computer Arithmetic and Login Unit Control Unit Internal CPU Interconnection Registers CPU I/O Memory System Bus CPU

Structure - The Control Unit CPU Control Memory Control Unit Registers and Decoders Sequencing Login Control Unit ALU Registers Internal Bus Control Unit

The Abstract Levels of Modern Computing Systems

Computer Evolution and Performance What is a Computer ?! Architecture & Organization ! Structure & Function ! Evolution & Performance !

Computer Evolution and Performance History of Computers: Mechanical Era (1600s-1940s) The Electronic Era (1940-Now)

Mechanical era summary: Mechanical computers were designed to reduce the time required for calculations and increase accuracy of the results Two drawbacks: —Speed of operation limited by the inertia of moving parts (gears and pulleys) —Cumbersome, unreliable, and expensive

The Electronic Era: Generation 1 ( ) Generation 2 ( ) Generation 3 ( ) Generation 4 ( present) Generation 5 (? - ?)

Computer Generation 1 : ENIAC —Developed for calculating artillery firing tables —Designed by Mauchly and Echert of the University of Pennsylvania —Generally regarded as the first electronic computer –Colossus probably the first, but was classified until recently —BIG! –18,000 tubes,70,000 resistors –10,000 capacitors,6,000 switches –30 x 50 feet,140 kW of power —Decimal number system used —Programmed by manually setting switches

Computer Generation 1 : IAS (Institute for Advanced Studies) —von Neumann and Goldstine —Took idea of ENIAC and developed concept of storing a program in the memory —This architecture came to be known as the “von Neumann” architecture and has been the basis for virtually every machine designed since then —Features –Data and instructions (programs) are stored in a single read-write memory –Memory contents are addressable by location, regardless of the content itself –Sequential execution

von Neumann/Turing Stored Program concept Main memory storing programs and data ALU operating on binary data Control unit interpreting instructions from memory and executing Input and output equipment operated by control unit Princeton Institute for Advanced Studies —IAS Completed 1952

Structure of von Neumann machine

IAS Memory Formats

IAS - details 1000 x 40 bit words —Binary number —2 x 20 bit instructions Set of registers (storage in CPU) —Memory Buffer Register —Memory Address Register —Instruction Register —Instruction Buffer Register —Program Counter —Accumulator —Multiplier Quotient

Structure of IAS – detail

Commercial Computers Eckert-Mauchly Computer Corporation UNIVAC I (Universal Automatic Computer) US Bureau of Census 1950 calculations Became part of Sperry-Rand Corporation Late 1950s - UNIVAC II —Faster —More memory

IBM Punched-card processing equipment the 701 —IBM’s first stored program computer —Scientific calculations the 702 —Business applications Lead to 700/7000 series

Computer Generation 2 : Generation 2 ( ) — Technology change — Transistors — High level languages — Floating point arithmetic

Transistors Replaced vacuum tubes Smaller Cheaper Less heat dissipation Solid State device Made from Silicon (Sand) Invented 1947 at Bell Labs William Shockley et al.

Transistor Based Computers Second generation machines NCR & RCA produced small transistor machines IBM 7000 DEC —Produced PDP-1

Computer Generation 3 : Generation 3 ( ) — Introduction of integrated — Semiconductor memory — Microprogramming — Multiprogramming

Microelectronics Literally - “small electronics” A computer is made up of gates, memory cells and interconnections These can be manufactured on a semiconductor e.g. silicon wafer

Computer Generation 4 : Generation 4 ( present) — Large scale integration / VLSI — Single board computers

Computer Generation 5 : Generation 5 (? - ?) — VLSI / ULSI — Computer communications networks — Artificial intelligence — Massively parallel machines

Generations of Computer Vacuum tube Transistor Small scale integration on —Up to 100 devices on a chip Medium scale integration - to 1971 —100-3,000 devices on a chip Large scale integration —3, ,000 devices on a chip Very large scale integration to date —100, ,000,000 devices on a chip Ultra large scale integration —Over 100,000,000 devices on a chip

Summary of Generations

Moore’s Law Increased density of components on chip Gordon Moore - cofounder of Intel Number of transistors on a chip will double every year Since 1970’s development has slowed a little —Number of transistors doubles every 18 months Cost of a chip has remained almost unchanged Higher packing density means shorter electrical paths, giving higher performance Smaller size gives increased flexibility Reduced power and cooling requirements Fewer interconnections increases reliability

Growth in CPU Transistor Count

Pentium and PowerPC Evolution Pentium represents the results of decades of design effort on complex instructions set computers (CISCs). It incorporates the sophisticated design principles once found only on mainframes and supercomputers and servers as an excellent example of CISC design. The PowerPC is a direct descendant of the first RISC system, the IBM 801, and is one of the most powerful and best-designed RISC-based systems on market.

Intel —First microprocessor —All CPU components on a single chip —4 bit Followed in 1972 by 8008 —8 bit —Both designed for specific applications —Intel’s first general purpose microprocessor

Pentium Evolution (1) 8080 —first general purpose microprocessor —8 bit data path —Used in first personal computer – Altair 8086 —much more powerful —16 bit —instruction cache, prefetch few instructions —8088 (8 bit external bus) used in first IBM PC —16 Mbyte memory addressable —up from 1Mb —32 bit —Support for multitasking

Pentium Evolution (2) —sophisticated powerful cache and instruction pipelining —built in maths co-processor Pentium —Superscalar —Multiple instructions executed in parallel Pentium Pro —Increased superscalar organization —Aggressive register renaming —branch prediction —data flow analysis —speculative execution

Pentium Evolution (3) Pentium II —MMX technology —graphics, video & audio processing Pentium III —Additional floating point instructions for 3D graphics Pentium 4 —Note Arabic rather than Roman numerals —Further floating point and multimedia enhancements Itanium —64 bit (chapter 15) Itanium 2 —Hardware enhancements to increase speed See Intel web pages for detailed inf. on process.

PowerPC Evolution

Performance Mismatch Processor speed increased Memory capacity increased Memory speed lags behind processor speed

DRAM and Processor Characteristics

Solutions Increase number of bits retrieved at one time —Make DRAM “wider” rather than “deeper” Change DRAM interface —Cache Reduce frequency of memory access —More complex cache and cache on chip Increase interconnection bandwidth —High speed buses —Hierarchy of buses

Questions and comments!